As with nearly all 16 bit RPGs, characters in the classic series underwent some changes when the games were localized. For most of them, it was just a name change. Rolf is Rolf, regardless of his name. Mieu is one of those few exceptions that had more drastic changes.
In the Japan version, Mieu is about 600 years old, meaning that, like Demi, she was built after the technologically advanced civilization began to regress to a more primitive state. She spent a long time deactivated, so she's not that old mentally. Exactly how long she was offline wasn't revealed, so she could be around Rhys' age in mind. She was also avoiding towns because people tended to stare and crowd around her because of her unusual appearance.
The English version changed a lot of that. She's over 1,000 years old, making her part of the Laya-Orkaio war. There's nothing to suggest she was ever deactivated, so she's much older than in the Japan version in mind and spirit. She's now been waiting for a member of Rhys' bloodline, apparently wandering around the whole time. No reason is given for why she avoids people, but she's apparently strange enough that the townsfolk think she is a Layan.
So, which of these versions do you think makes for the best version of the character?